1. Field of the Invention
The present invention relates to a liquid ejection apparatus, a nanoimprint system, and a liquid ejection method, and particularly to a liquid ejection technology for ejecting functional liquid on a substrate using an inkjet printing system.
2. Description of the Related Art
An inkjet recording apparatus for forming an image on a medium by ejecting fine liquid droplets from an inkjet head has been widely used as a general-purpose image forming apparatus in homes and offices. In recent years, the inkjet printing system has been applied for the industrial purposes such as in electronics in which liquid containing metal particles or photosensitive resin particles is ejected to render a predetermined pattern on a substrate.
With size reduction and high integration of semiconductor integrated circuits, there has been known, as a technology for forming a fine structure on a substrate, nanoimprint lithography (NIL) in which a stamper having a desired irregular pattern to be transferred is pressed against a resist (UV hardening resin) applied to a substrate, and ultraviolet light is radiated to the resist to cure the resist, while the stamper is pressed against the resist, and then the stamper is released (remolded) from the resist on the substrate, thereby transferring the fine pattern formed on the stamper to the substrate (resist).
The use of the inkjet printing system has been proposed as the application of resist fluid in NIL. The resist fluid is discretely disposed in accordance with the irregular pattern formed on the stamper, and a pattern of the resist fluid can be formed uniformly by pressing the stamper.
The liquid ejection technology using the inkjet printing system has been used in this manner for various purposes other than in graphics.
Patent Document 1 (Japanese Patent Application Publication No. 2007-152349) discloses an apparatus configuration that ejects liquid containing functional materials from an injection head to a substrate. The apparatus configuration disclosed in Patent Document 1 has a configuration for relatively moving the substrate and the injection head in the x- and y-directions and rotational position adjustment for adjusting a displacement in a rotational direction in the xy plane.
Patent Documents 2 (Japanese Translation of PCT Application No. 2008-502157) and Patent Document 3 (Japanese Patent Application Publication No. 2009-88376) each disclose a system for applying liquid of an imprint material to a substrate by using an inkjet printing system. Each of the systems disclosed in Patent Documents 2 and 3 is configured to optimize the deposited droplet amount by changing a deposition density or deposited droplet amount in accordance with a volatilization volume of the pattern or the imprint material (resist) when distributing a certain amount of liquid on the substrate, to improve throughput and uniform the residue thickness.